Field
The present disclosure generally relates to the field of electronics, and more particularly, to radio frequency switches.
Description of Related Art
In antenna tuning and other radio frequency (RF) switching applications, a plurality of switching elements (e.g., often field-effect transistors (FETs)) are used as passive components. The plurality of switching elements are coupled in series to form a stack. The stack configuration enables a number of functions, including voltage and power handling capacity. For example, a FET stack is often utilized to allow an RF switch to bear high power under mismatch conditions. It is desirable for a FET stack in an off state to handle relatively high voltage swings by evenly distributing applied voltage across the FETs (i.e., switches) in the stack. However, each FET in a stack often has a different parasitic loading to the substrate than the other FETs in the stack, which causes uneven drain-to-source swings to develop. Consequently, the top several FETs of a stack are forced to bear a disproportionate percentage of the total voltage swing, and are thus more likely to be a point of failure for the stack.